Socket wrenches incorporating ratchet drives and standard sockets for driving threaded fasteners including most commonly hexagonal nuts and bolt heads are commonly used in the mechanic's field. In situations where a mechanic is confronted with the requirement for driving a fastener located in a tight space restricting the swing of the drive ratchet handle, extension drives are utilized to transmit the force from the ratchet to the socket. When driving a fastener in a remote location and particularly in a situation where the work must be accomplished in close quarters and with obstructions present, it is desirable to have a mechanism by which the socket can be locked to the extension. In addition to the desirability of a locking feature, it is necessary to provide for the rapid changing of sockets for driving various sizes of fasteners. In the environment in which a mechanic works, for example, in repairing vehicles or machinery, the mechanic often encounters an adverse environment involving temperature variations, corroded or damaged fasteners time pressures regarding the completion of jobs as well as oily and greasy conditions rendering a positive locking and releasing feature desirable. Under these situation, it is deisrable for any mechanism to be simple and reliable as well as durable while providing an effective means of improving the efficiency of the work. Another requirement for mechanic's tools is that they be relatively simple to manufacture and maintain.
Various methods are known by which fastener drive sockets can be affixed to mechanisms with which to drive those sockets. Most of the known systems involve methods tailored to specific needs providing positive locking mechanisms for tools such as impact wrenches, where it is essential from a safety standpoint to have the sockets firmly attached to the drive. In these applications complicated machining may be utilized since the drive mechanisms are of relatively large size and bulk providing adequate strength despite extensive internal machining. In addition, these mechanisms are all devised to be utilized in a location where the operator is provided ample work space and compactness of the mechanism is not an important factor. Known mechanisms incorporate locking means such as external rotating collars which are unsuitable for application in close quarters due to the possibility of accidental release from friction with obstructions (Rhinevault U.S. Pat. No. 2,162,353). Other mechanisms involve plungers as locking mechanisms which must be released utilizing a separate tool (Beers U.S. Pat. No. 2,954,934; Wendling U.S. Pat. No. 2,987,334). Other locking mechanisms involve the use of set screws, pins or other awkward releasing mechanisms requiring the removal of the socket from the fastener or workpiece and preventing rapid releasing of sockets in work in close quarters (Coffman U.S. Pat. No. 2,667,562).
One other type of mechanism known in an application similar to that for the instant invention is a push button release for a ratchet socket drive. This mechanism is unlike the invention in that it requires relatively complicated machining as does the other prior art, is relatively difficult to maintain and subject to malfunction from dirt or wear, is unsuitable for use on extensions because of the utilization of a central axial bore and pushbutton, and finally, involves application of both a downward pressure on a pushbutton plunger while requiring the resistance against which this force is applied as well as the simultaneous movement of the socket in the same direction as the pushbutton and in the direction opposite the resistance, which is an awkward motion for a mechanic in tight spaces. The pushbutton ratchet release also requires that the mechanism be machined out of larger pieces for the same strength as non-machined parts, rendering it frequently difficult to utilize the ratchet and socket combination alone in tight spaces (Smyers U.S. Pat. No. 3,762,245).
The invention provides for the utilization of the locking and quick releasing feature as a supplement to the ratchet handle which may be made smaller yet stronger than the cumbersome quick release type ratchet handle.